The document EP 1 894 442 in the name of the applicant describes a mold equipped with an induction heating device and cooling device using the circulation of a heat-transfer fluid. That device of the prior art comprises a mold made up of a fixed part and a mobile part. Each of the parts can receive an induction heating circuit and a cooling circuit. Each of these parts consists of a carcass to which a part is added to make up the molding surface, giving its final shape to the workpiece made in the mold For each part of the mold, the molding surface is the surface to heat and cool, which surface is in contact with the material making up the workpiece. The inductors are placed in cavities that extend under said molding surface. These cavities are most often made by grooving the underside of said molding zone at the interface between that zone and the carcass of the mold. For its part, the cooling circuit is made with conduits drilled in the carcass, which are further away from the molding surface. That cooling circuit carries out both the cooling of the carcass, which, in a common embodiment, is made in material that is relatively insensitive to induction heating, and the cooling of the molding surface. Finally, the carcass of each part is mechanically joined to a support.
That configuration provides satisfactory results but is difficult to implement when the mold is large or when the molding surface has a complex shape. In such conditions, the temperature gradients that occur both during heating and cooling lead to the distortion of the shape of the mold overall, and secondly, on a smaller scale, differential distortion between the molding zone and the carcass, which differential distortion leads to poor contact between these two elements and has an adverse effect on the quality of the cooling, by creating thermal barriers between said two elements, due to the differential distortion.